Electric switch



Dec. 7, 1926. 1,609,801

H. A. DOUGLAS ELECTRIC SWITCH Filed Sept. 11. 1925 g fla [7 @239 L% @aglab.

Patented Dec. 7, 1926.

UNITED STATES HARRY A. DOUGLAS, or Bronson, MICHIGAN.

ELECTRIC swri'cn.

Application and September 11, 1925'. Serial No. 55,757".

My invention relates to electric switches and is of particular service in connection with those electric switches that are employed upon automobiles for the regulation of their ignition and lighting circuits, though the invention is not to be restricted to any particular use to which it may be put.

A switch to which my invention is applicable is disclosed in my United States Patent 1,516,765, dated November 25, 1924. In the structure disclosed in said patent, there is a casing for holding the operating switch parts this casing having a contact carrying wall at one end and aswitch actuating handle having parts passing through the casing wall at the other end into actuating relation with a contact actuator, and a lock carried by the handle and also having a portion extending into the casing and there having operative connection with another contact actuator. In the device of said patent the contact carrying end wall of the casing is in the form of a disc of insulation that is made thick in order that it may be of sufficient strength and body to rigidly hold the contactsthat it supports.

My invention has for its object to lighten the structure of said contact carrying end wall without impairing the strength thereof while preferably retaining the desired separable assembly of it with the balance of the casing and the rigid mounting thereon of the metallic contacts carried thereby. In carrying out my invention I form the casing end wall of sheet metal and preferably shape it into a shallow cup which desirably carries bayonet pins or projections upon its side or rim for assembling it with and within the surrounding side or cylindrical wall of the casing. The metallic contacts are carried in bushings of insulation that are passed through the metallic. casing end wall. these bushings and said casing end wall being so related as to prevent the bushings from turning in their support. In the preferred embodiment of the invention this result is accomplished by joining the inner ends of the bushings by a bridge piece which also serves to guide the movable contacts into and out of connection with the fixed contacts upon the bushings. This bridge piece is preferably of insulation and integrally formed with the bushings. I do not wish to ,be limited to its continuous or unbroken connection with the bushings in so far as its contactguiding function is concerned. The insulating bushings and the metallic contacts supported thereby are provided with interengagin'g formations which prevent the contacts from turning with respect to the bushings carrying the same. These contacts are formed with threaded bores that receive metallic bindingscrews which hold circuit wires or conductors in firm electrical and mechanical connection with the contacts and in firm mechanical assembly with the contact carrying metallic end wall owing to the fixed relation of the contacts and bushings and of the bushings and end wall. Any reasonable degree of turning effort may be efiectively supplied to' the binding screws without disturbing the fixed relation of contacts, bushings and the casing end wall.

The invention will be more fully eX- plained in connection with the accompanying drawing. inwhich Fig. 1 is a rear view of the preferred form of the invention, parts being broken away; Fig. 2 is a sectional view on line 2-2 of Fig. 1; Fig. is a sectional view on line 3- 3 O'f Fig. 2; Fig. 4 isa sectional view on line 4 4: of Fig. 2; and Fig; 5 is a sectional view on line 55 of Fig. 1.

The casing has an end wall 1 and a side wall 2, the wall 1 being essentially fiat and the wall 2 being preferably cylindrical; A mounting plate 3 is disposed over the end wall and upon the exterior of the casing beyond which the mounting' plate laterally projects. The mounting plate is desirably circular and coaxial with the casing and through whicha large circular opening 7 is formed, this opening being likewise coaxial with the casing and plate. One or more arcuate slots 8 also concentric with the casing, are formed through the endwall thereof and are aligned with the opening 7, these slots being formed indepressedportions9. The end wall of the casing and the mounting plate are spaced apart toreceive arcuate flanges'l l formed upon one end of the handle 11, the' flanges, the end wall of the casing. and the. casing mounting plate cooperating to define a plane ofzrotation or oscillation for the bandle. The switching mechanism includes an actuating member 12 here shown as being in the form of a ring. This ring is formed with widenotches 13 upon: its inner circular face. These notches receive the handle port-ions 14 which project intothe interior of I the casing through the arcuate slots 8. Said notches or openings are of such shape as to prevent material relative turning movement between the handle and actuating member while desirably permitting sliding movement of the actuating member upon the handle.

A contact carrier 15 in the form of a metallic plate shaped into a shallow cup carries bayonet pins or projections 16 upon its circular wall or rim that are receivable in bayonet slots or channels 17 formed in the cylindrical wall of the casing. This contact carrier carries metallic contacts 18, 19, 20, etc, which pertain to the different circuits, the circuit relation thereof being immaterial so far as my invention is concerned. These contacts are shown in the form, of hexagonal rods that fit the hexagonal bores in insulating bushings 15. The bushings are preferably individually formed upon the outside of the metallic end wall 15 and have inner bridge portions 15 preterably raised above the general plane of the end wall 15 substantially to the level of and interposed between the inner ends oi? the bushings and upon which the traveling switch members ride, as will appear. These bridge portions are preferably ,non-metallic, being desirably of insulation and molded integrally with the bushings. This construction prevents the outward passage of the bushings through the metallic end wall 15 due to the engagement of said bridge portion with the inner side of said end wall, said bushings being reduced in diameter in the zone or the flat portion of the metallic plate 15 to form: annular recesses in which said plate is securely received and in a manner to prevent inward movement of the bushings- The bushings and their connecting bridge portions may be molded into assembly with the end wall 15. The bridge portion 15 that unites the bushings prevents them :trom turning on their own axes and with respect to the end wall 15. The hexagonal rod contacts 18,19,20,etc., pass through the hexagonal bores of the bushings so as to be accessible for switching engagement at their inner ends and for circuit connection at their outer ends. These bushings and contacts are thus provided with interengaging formations at unequal distances from their common axes whereby the contacts can not turn with respect to the bushings and as the bushings are in fixed relation with the end wall 15, said contacts can not turn with respect to said end wall. The metallic binding screws 21 may thus be turned with any reasonable degree of force to secure effective connection therewith of circuit wires or conductors Without disturbing the firm and fixed mechanical relation of the metallic end Wall, the bushings carried thereby, and the contacts carried by the bushings. The bridge portion 15 may be formed with socket recesses 15 to hold the traveling contacts that are not in circuit closing position. The inner ends or the contact rods 18, etc, are slightly dished so as to receive contacts that are provided upon one or more contact carriers that are supplied in addition to the contact carrier 15. Another contact carrier 22 is interposed between the contact carrier 15 and the contact actuator 12, the contact carrier 22 being desirably in the form. of a metallic ring which is co-axial with the actuating member 12- and the switch casing. The ring 22 carries a series ot metallic contacts which are formed. with spring barrels 2 1- that have clinching formations 25 upon one side of the ring to hold this ring in iirm assembly with the contacts 23 upon the other side of this ring.

T he metallic spring barrels 2 1 are received within the cups 12, formed of insulation. and have sliding engagement with the side walls ot' these cups. The contact actuator 12 is preferably of sheet steel and has cup tormations 12 that receive the cups 12 ct insulation, the bottoms of the cups 12 resting against the bottoms of the cups 12 Further to define the position of the cups 12 in the cups 12 1 form the cups 12 with rims 0r flanges that bear upon the body of the contact actuator 12. The contacts 23 are pressed toward the carrier 15 and the contact actuating ring 12 is pressed against the depressed portion 9 of the end wall 1 of the casing by means of coiled springs 25 that are located within the spring barrels 24, these coiled springs pressing each at one end upon the contacts 23 and each at its other end against the metallic plungers 26 that are pressed against the bottoms of the cups 12'.

There is a central sleeve 27 that is co-axial with the handle and with. the casing and other rotating parts oi? the switch. This sleeve houses the barrel 29 of any suitable lock which is accessible trom the front oi? the handle. The sleeve is shown with slots 30 into which the tumblers 31 ot the lock may be projected when operated by a key in order to lock the inner contact carrier 32 and from which the tumblers may be withdrawn when the contact carrier 32 is to be unlocked and readjusted, the ban lle controlled switch being preferably always adjustable.

The rotating part of the lock carries a projection 33 which extends into the switch casing through a central opening in the end wall 1 of the casing. A. contact actuator 3 1 is formed With an opening that receives the projection 33, this opening being of such shape as to prevent material relative turning movement between the actuator 34 and the projection 33 but permitting sliding movement of this actuator 34 upon the lock projection 33. The contact carrier 32 is interposed. between the contact carrier 15 and the contact actuator 34. This contact carrier 32 is shown as being in the form of a triangular plate. It has a central depression 35 which is received upon the inner end of the central contact 19 in the contact carrier 15, these portions 35 and 19 constituting complemental. contacts as the switch is illustrated. The contact carrying plate 32 is thus obviously mounted to be turned to the extent defined by the turning movement of the lock projection 33 through the intermediation of parts now to be described.

The contact plate 32 carries spring barrels 36 and springs 37 within the spring barrels, these springs projecting the plungers 38 through the front ends of these spring barrels. The contact actuator 34:, being desirably of sheet steel, is formed with cups 39 which receive the cups 40, of insulation, in a manner similar to the reception of the cups 112 in the cups 12 of the contact actuator 12. The spring barrels 36 have sliding engagement with the side walls of the cups 40,.

and the spring-pressed plungers 38 have engagement with the end walls of these cups. In this way the contact carrier 32 is coupled with the contact actuator 34;. The springs in the various spring barrels permit the contact carriers to reciprocate as the contacts on these carriers ride into and out of engagement with the contacts upon the contact carrier 15.

Changes may be made without departing from my invention.

Having thus described my invention, I claim as new 1. An electric switchinc-luding a casing therefor having a sheet metal end wall; a plurality of insulating bushings formed with bores and carried by said end wall; a traveling contact member within the casing; an actuator for said traveling contact member and having an operating member extending to the exterior of the casing; and contacts carried by said bushings'in the bores of the bushings and being accessible for engagement within the casing by said traveling contact member, there being a bridging portion between said bushin s that is positioned to be engaged by said traveling contact member in moving between the contacts carried bythe bushings.

2. An electric switch including a casing therefor having a sheet metal. end wall; a plurality of insulating bushings formed with bores and carried by said end wall and projecting into the interior of the casing; contacts carried by said bushings in the bores of the bushings and being accessible for en gagement within the casing; a traveling contact member with the casing, there being a raised bridging portion between the inner ends of said bushings positioned to be engaged by the traveling contact member; and an actuator for said traveling contact member and having an operating member extending to the exterior of the casing.

3. An electric switch including a casing therefor having a sheet metal end wall; a plurality of insulating bushings formed with bores and carried by said end wall; a traveling contact member within the casing; an actuator for said traveling contact member and having an operating member extend.- ing to the exterior of the casing; contacts carried by said bushings in the bores of the bushings and being accessible for engage ment within the casing by said traveling contact member and a bridging portion be tween and integrally formed with said bushings and positioned to be engaged by said traveling contact member in moving between the contacts carried by the bushings.

4. An electric switch including a casing therefor having a sheet metal end wall; a plurality of insulating bushings formed with bores and carried by said end wall and projecting into the interior of the casing; contacts carried by said bushings in the bores of the bushings and being accessible for engage ment within the casing; a traveling con tact member within the casing; an actuator for said traveling contact member and having an operating member extending to the exterior of the casing; and a bridging portion integrally formed with the inner ends of the bushings and positioned to be engaged by said traveling contact member.

5. An electric switch including a casing therefor having a sheet metal end wall; a plurality of insulating bushings formed with bores, and carried by said end wall and projecting into the interior of the casing; contacts carried by said bushings in the bores of the bushings and being accessible for engagement within the casing; a traveling contact member within the casing; an actuator for said traveling contact member and having an operating member extending to the exterior of the casing; and a raised bridging portion integrally formed with the inner ends of the bushings and positioned to be engaged by said traveling contact member.

In witness whereof, I hereunto subscribe my name.

HARRY A. DOUGLAS. 

